Portsmouth North
South East · Borough constituency · Portsmouth borough
About the Portsmouth North constituency
Portsmouth North is a borough constituency in the South East, covering most or all of Portsmouth. The sitting MP is Amanda Martin (Labour), first elected in July 2024.
At the 2024 general election, Labour won Portsmouth North with 34.9% of the vote, ahead of the Conservatives on 33.0%, a majority of 780 votes. Turnout was 59.0%.
If a general election were held today, PollCheck's projection at the current seven-poll average has Reform UK on 36.0% and the Conservatives on 25.1% in Portsmouth North, a margin of 10.9 points, a projected change from Labour since 2024. The projection updates automatically as new polls are added.
Demographically, Portsmouth North is a strongly Leave-voting area (an estimated 63.7% voted Leave in 2016). About 26.5% of residents hold a degree, 63.8% of homes are owner-occupied, and the seat has a median age of about 39 (2021 Census).
Across the last 5 general elections on record, the seat has been won by the Conservatives 4 times, Labour 1 time (earlier years may be on predecessor boundaries).
Who lives in Portsmouth North? Constituency demographics
From the 2021 Census and 2016 EU referendum estimates. Constituency-level data on 2024 boundaries.
How did Portsmouth North vote in 2024 and how would it vote now?
2024 vote shares from the HoC Library. Current projection is at the 7-poll average.
2024 general election
Current projection
Map of Portsmouth North
Switch between ward-level 2024 election winners and a demographic view. Ward winners are Britain Elects' / New Statesman modelled estimates with an average ~4pp margin of error per ward. The demographic view splits the seat into small neighbourhoods (around 1,500 residents each, from the 2021 Census). Hover any area for detail.
Portsmouth North within Portsmouth
The Westminster constituency of Portsmouth North sits entirely within Portsmouth Council. Local council elections are a separate ballot from Westminster general elections - the figures below are from the council elections held on Thursday 7 May 2026.
Council overlap
| Council | Share of seat | Projection |
|---|---|---|
| Portsmouth | 100% | View projection › |
Most recent council ward results
Latest council winner per ward. Where the council held a May 2026 election, those results are shown; otherwise we show the most recent available ward result (via DCLEAPIL, 2014-2024), or, where the seat was uncontested at the last election, the current sitting councillor from OpenCouncilData. The "Shift since GE2024" column is only computed for May 2026 results - earlier council votes pre-date the GE, so no directional shift is shown.
| Ward | GE2024 winner | Latest council winner | Shift since GE2024 | Turnout |
|---|
Projection trajectory
PollCheck's projection for Portsmouth North at each of the last 60 GB polls. Hover the chart for the underlying poll details.
Who has won Portsmouth North at past general elections?
2024 result is on current boundaries. The 2019 row is the UK Parliament's notional recalculation onto the 2024 boundaries (directly comparable to 2024). The 2010, 2015 and 2017 rows are on the boundaries in force at the time and aren't directly comparable.
| Year | Result | MP | Lab | Con | LD | Majority | Turnout |
|---|---|---|---|---|---|---|---|
| 2010 | Con gain from Lab | Penny Mordaunt | 27.8% | 44.3% | 20.1% | 7,289 | 62.7% |
| 2015 | Con hold | Penny Mordaunt | 23.8% | 47.0% | 6.2% | 10,537 | 62.1%-0.6 |
| 2017 | Con hold | Penny Mordaunt | 33.7% | 54.8% | 5.5% | 9,965 | 66.1%+4.0 |
| 2019notional | Conservative winner | Penny Mordaunt 2019 MP, pre-review boundary | 27.0% | 61.4% | 7.4% | 15,780 | 63.9%-2.2 |
| 2024 | Lab gain from Con | Amanda Martin | 34.8% | 33.0% | 7.3% | 780 | 59.0%-4.9 |
Earlier years are on pre-2024 boundaries; comparable results on the new boundary will be added when sourced.
Constituencies most like Portsmouth North
Five seats with similar demographic profiles to Portsmouth North. Politics shown for context.
- ↑Leave63.7 / 63.7vs 53.2
- ↓Graduate26.5 / 26.9vs 33.7
- ↑Employed61.7 / 60.7vs 57.3
- ↑Leave63.7 / 61.0vs 53.2
- ↓Graduate26.5 / 28.4vs 33.7
- ↑Employed61.7 / 61.8vs 57.3
- ↑Leave63.7 / 61.6vs 53.2
- ↓Graduate26.5 / 24.1vs 33.7
- ↑Employed61.7 / 61.4vs 57.3
- ↑Leave63.7 / 63.9vs 53.2
- ↓Graduate26.5 / 24.4vs 33.7
- ↑Employed61.7 / 60.8vs 57.3
- ↓Graduate26.5 / 26.8vs 33.7
- ↑Leave63.7 / 60.1vs 53.2
- ↑Employed61.7 / 62.8vs 57.3
What would change this seat?
Move the sliders to set national vote shares. The per-seat projection updates live. Reset returns to the current 7-poll average.
Related
Sources
- 2024 general election results · UK Parliament Election Results portal and House of Commons Library briefing CBP-10009.
- Notional 2019 results on 2024 boundaries · UK Parliament Election Results portal. Recalculated by Parliament; carries assumptions about how 2019 voters would have distributed across the redrawn boundaries.
- Historic general election results (2010-2017) · House of Commons Library historic results files (on the boundaries in force at the time).
- Ward-level GE2024 estimates · Britain Elects / New Statesman - article by Ben Walker, underlying spreadsheet. Modelled from constituency totals; average ~4pp per-ward MoE.
- May 2026 council ward results · Democracy Club via PollCheck's locals 2026 dataset.
- Earlier council ward results (2014-2024) · DCLEAPIL v1.0 (Jason Leman, drawing on Andrew Teale's LEAP dataset and Democracy Club).
- Demographics · ONS Census 2021 (England and Wales), aggregated to constituency level using the ONS LSOA21 -> PCON24 best-fit lookup.
- EU referendum 2016 estimates · Constituency-level Leave vote estimates (Hanretty 2017 method).
- MP details and Cabinet roles · UK Parliament Members API. MP photos are fetched live from the same source.
- Boundary geometry and lookups · ONS Open Geography Portal (PCON24 boundaries, LSOA21 boundaries, LSOA21-WD24-LAD24 best-fit lookup).
- Current projection and trajectory · PollCheck's demographic swingometer applied to the rolling 7-poll average from aggregated GB polls. Not a true MRP - vote-share movements are applied through per-constituency sensitivity multipliers derived from demographic regressions.
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